Exogenous application of phytohormones modulates the antioxidant enzyme system to induce terminal heat stress tolerance in chickpea.A

Heat stress has been considered as vital ecological feature to affect the plant growth and productivity. Rising temperature due to global warming resulting in heat stress that restricting the plant growth and potential productivity throughout the world. Therefore, a field experiment was carried out at Bahauddin Zakariya University Multan, Pakistan to minimize the heat stress induced-losses in chickpea plants with the foliar spray of phytohormones during two consecutive years 2017-18 and 2018-19. Experimental treatments comprising of two chickpea cultivars (DHUST and Bhakkar, 2011) were cultivated on two different sowing dates (15th November and 1st December) and foliar spray of phytohormones (Benzyl-amino purine (BAP) and Moringa leaf extract (MLE30)) including tap water as a control. Results suggested that heat stress severely reduced the chickpea growth and productivity. However, exogenous application of MLE had a tremendous effect on the studied attributes. Exogenous application of MLE improved the growth and yield contributing attributes, which ultimately increased the final productivity. Moreover, foliar spray of MLE significantly modulated superoxide dismutase, peroxidase and catalase enzymatic activities and minimized the adverse impacts of heat stress on yield contributing traits. Our results suggested that foliar spray of phytohormones particularly MLE modulated the heat stress induced losses to chickpea cultivar Bhakkar 2011 by improving their antioxidant defense mechanism and enhanced the productivity. (author)